Al Gore, the former American vice-president and Nobel Peace prize winner, spoke on the second day of the Climate Reality Leadership Corps training in Johannesburg on Thursday. The event drew environmental thinkers and activists from around the continent.
The corps is a global movement to teach people about climate change and help them adapt to a changing world.

In his presentation, Gore gave an overview of how humans were driving climate change and how it was affecting conditions around the world right now.

"Whenever any important question is ultimately resolved into a choice between right and wrong, the outcome becomes inevitable." The current global system was destroying the habitability of the planet by burning fossil fuels, Gore said, adding that it was wrong and needed to change. "We can see the pathway ahead very clearly and we are going to prevail."

Showing a timelapse map of world temperatures since 1884 – when most modern records began – he illustrated how the entire globe was getting hotter on average. Last year was the 37th consecutive year where the average temperature was above the 20th century average. "As the average goes up, the extremes go up," he said. The last decade was the hottest on record.

'Man-made pollution'
This was, according to him, because humans were pumping gases into the atmosphere and driving global warming – 90-million tonnes of carbon dioxide and other greenhouse gases every day. With the atmosphere being as thin as a coat of varnish on a globe, the impact was devastating. "The accumulated man-made pollution in the atmosphere traps as much heats as 400 000 Hiroshima-scale atomic bombs every day. It is a big planet, but that is a lot of heat energy," he said.

The number of warmer days had rapidly increased since the 1980s as a result. Extreme cold and hot days used to occur 0.1% of the time, now they happen 10% of the time.

In the last year, this had brought about a critical shift in how scientists talk about global warming. In the past they said it increased the odds of weird climate events – like floods and droughts. "Now they are saying all events are influenced by global warming."

An example was Typhoon Haiyan, which hit the Philippines last year. The ocean it passed over was 3°C warmer than usual, so it gained more energy and more water. The same went for Hurricane Sandy, which devastated the north-eastern coast of the United States. The oceans that fuelled it were 5°C warmer than usual. This made the storms more devastating than they otherwise would have been.

In the past three decades, the average humidity of the world increased by 4%. Global warming will accelerate this – for every 1°C increase in temperature, there is a 7% increase in the amount of humidity that the atmosphere can hold. This leads to more evaporation, heavier rain and worse storms. But it also leads to more evaporation and water being sucked out of the top layers of soil. This leads to drought. "As temperatures increase, we will get bigger downpours and longer droughts," he said.

This has profound impacts for countries that were already on the edge. In the years leading up to its civil war, Syria lost 80% of its cattle and 60% of its crops because of droughts. A million people moved to the cities as a result. "The political consequences of the drought were beyond the government's capacity to deal with. Now we see the results," he said.

SA projected to get drier
Only North America, Australia and South America were net exporters of food. This left the world vulnerable to food shocks, and in countries where people spend 60% of their money on food this led to food riots.

In Sub-Saharan Africa, the impacts would be even more profound. A 2°C increase in temperatures would lead to a 40% to 80% decrease in maize and millet production. These are the area's staple food. The areas where coffee could be grown in Uganda would basically disappear with a 2°C increase – and the world's average temperature is projected to increase by 4°C by the end of the century.

South Africa's other plants, which, Gore said, make it one of a few mega-diverse countries countries in the world, faced extinction. With a 1.5°C increase half of all local plant species would be lost.

Water would be the most profoundly felt impact of climate change. South Africa is projected to get much drier – it is already the 31st driest country in the world – with demand exceeding supply by 17% by 2030. Gore said elsewhere in Africa water shortages were already forcing people into conflict. Lake Turkana in Kenya was so dry that people would move to where it rained, but would not be welcomed by locals who did not want to share the scarce resource.

Driving force behind climate change
And while climate change was happening, the world's leaders were still discussing the merits of whether humans were driving climate change. In the last year, only one of the over 9 000 peer-reviewed studies on climate change and global warming did not agree that humans were driving the process.

The key was to move towards adapting to climate change – changing the way we live to survive the change – and mitigating by reducing our greenhouse gas emission, he said. South Africa was lagging behind because of its commitment to coal and the subsidies that went towards this. "Production of electricity by coal in South Africa is very expensive and unreliable, as you have seen this year," he said. But the country was rated the world's most promising emerging market for solar energy and other renewable energy. By 2020, 80% of the world's population would be living in countries where solar electricity is cheaper than fuel from coal and other sources. This was a game changer. "The future is renewable," he said.

With climate change happening now and with sizeable impacts projected, the change had to happen now. "We are going to win this struggle. Don't have any doubt about that," said Gore.